Grasper bar positioning mechanism for automatic doffer

ABSTRACT

Bobbins are moved during doffing between a position upon and a position below the spindles of a textile spinning frame or like machine by a retractable mechanism disposed when not in use entirely below the spindles so as to not impede end-down or other servicing of the frame during normal spinning operations. Multiple guided connections with hydraulic cylinder and piston assemblies provide the smoothness and precision of grasper-bar movement necessary for successful performance of the bobbin doffing and donning operations. Critical components of the mechanism are shielded from the ambient atmosphere and from accidental impacts. Completion of each phase of the grasper bar&#39;&#39;s movement is verified before commencement of its next movement, and a photoelectric stop-motion device detects non-doffing of any bobbin.

United States Patent 1 1 Pray et 'al.

[ Jan. 22, 1974 GRASPER BAR POSITIONING MECHANISM FOR AUTOMATIC DOFFER [75] Inventors: Lester W. Pray, Clemson; John H.

Christeson, Seneca; Frederick A. Preston, Clemson; Herman D. Sheron, Jr., Seneca; William H. Drake; Gordon C. Anderson, both of Clemson, all of SC.

[73] Assignee: Maremont Corporation, Chicago,

22 Filed: Oct. 13, 1971 21 Appl.No.: 188,767

Related U.S. Application Data [63] Continuation of Ser. No. 864,399, Oct. 7, 1969,

abandoned.

[52] U.S. Cl. .57/52 [51] Int. Cl D01h 9/00 [58] Field of Search 57/34 R, 52-54 [56] References Cited UNITED STATES PATENTS 2,612,744 10/1952 Christianson 57/52 2,647,357 .8/1953 Watson et al 57/52 3,370,411 2/1968 Schulz et al. 57/52 3,398,519 8/1968 Haussmann 57/52 3,550,368 12/1970 Marenco 57/52 Primary Examiner.lohn Petrakes Attorney, Agent, or FirmDonald l-l. Feldman; Joseph H. Heard 57 I ABSTRACT Bobbins are moved during doffing between a position upon and a position below the spindles of a textile spinning frame or like machine by a retractable mechanism disposed when not in use entirely below the spindles so as to not impede end-down or other servicing of the frame during normal spinning operations. Multiple guided connections with hydraulic cylinder and piston assemblies provide the smoothness and precision of grasper-bar movement necessary for successful performance of the bobbin doffing and donning operations. Critical components of the mechanism are shielded from the ambient atmosphere and from accidental impacts. Completion of each phase of the grasper bars movement is verified before commencement of its next movement, and a photoelectric stopmotion device detects non-doffing of any bobbin.

10 Claims, 8 Drawing Figures GRASPER BAR POSITIONING MECHANISM FOR AUTOMATIC DOFFER This is a continuation of application Ser. No. 864,399, filed Oct. 7, 1969, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to automatic bobbin-doffing apparatus for textile spinning frames and like machines, such as twisters, and more particularly to the supporting and positioning mechanisms associated with the bobbin grasper bar of an automatic doffing apparatus such as disclosedin U. S. Pat. No. 3,370,41 l.

Such apparatus includes, on each side of the spinning frame being serviced, an elongate bobbin conveyor mounted beneath the spindle rail and the row of bobbin-receiving spindles thereon, and a vertically and laterally movable grasper bar having a plurality of depending bobbin-grasping elements corresponding in number and spacing to the spindles. During each doff- .ing operation, the grasper bar doffs full bobbins from all of the spindles simultaneously, transports them downwardly, and seats them upon upstanding pegs provided upon the conveyor. The conveyor then indexes sufficiently to align empty bobbins, (tubes) previously mounted upon alternate pegs of the conveyor, beneath the bobbin-grasping elements of the grasper bar. The empty bobbins are then transported upwardly to and donned upon the spindles. by the grasper bar, which thereafter returns to an inoperative position below the spindles and above the conveyor.

Among the many advantages of doffing apparatus of the foregoing type are its constant availability for operation when needed, stemmingfrom its permanentaffixation to the spinning frame being serviced. The apparatus is also quite rapid in operation, minimizing nonproductive down-time of the machinebeing serviced, since all bobbins are doffed from and donned upon the. full row of spindles at one time, rather than singly or in groups as with manual doffing or of other types of automatic doffing apparatus. However, thesevery advantages also give rise to certain problems and difficulties not'heretofore completely resolved.

Thus, the doffing apparatus permanent affixation to the spinning frame occasions its constant exposure to the ambient and frequently lint-contaminated atmosphere, and also to possible impacts as from cart traffic in the adjacent aisle and/or other abuse arising from the normal activity transpiring about or attendant the servicing of a spinning frame during normal spinning operations. It is also most important that the doffing apparatus not obstruct or otherwise inipede such normal servicing of the spinning frame. Various servicing operations, such as cleaning and end-down ing apparatus be disposed, in their inoperative position Similarly, while doffing and donning bobbins upon all of the spindles on one side of a spinning frame simultaneously yields the advantages previously noted, large motive forces and highly precise movements and alignments are required for satisfactory performance of such procedure. If the grasper bar should fail to doff a bobbin from even a single one of the spindles, as by reason of unevenness in and/or insufficient guiding of the grasper bars movement, and the doffing operation were allowed to proceed without correction of the failure, the doffing apparatus and/or spinning frame would be severely damaged. It is therefore highly desirable that the grasper bars movement be precisely guided and directed at all times, that it be smooth and uniform. and that verification of the completion of each phase of the bars movement and/or function be obtained before the doffing operation is allowed to proceed to a succeeding phase.

SUMMARY OF THE INVENTION The present invention provides, in a doffing apparatus of the type described, a mechanism for smoothly and precisely moving and guiding the grasper bar during each doffing operation between an elevated position above the spindles being serviced and a lowered inoperative position wherein the grasper bar and all components of the mechanism are disposed in their entireties below the spindles so as to not obstruct or otherwise impede manual or automatic cleaning, enddown piecing and/or other servicing of the spinning frame during normal spinning operations. Critical components of the mechanism are shielded from the ambientatmosphere and also from accidental impacts and stresses to which they might otherwise be subjected. In a preferred embodiment of the mechanism, completion of each phase of the grasper bars movement is verified before commencement of the succeeding movementphase, and stop-motion means detect inadvertent nondoffing of a bobbin from any one of the spindles being serviced.

In its more specifid aspects, the present mechanism includes an elongate cylindrical housing mounted for pivotal movement about its central axis upon the bobbin-conveyor track of the doffing apparatus, which track is of a unitary extruded construction greatly facilitating manufacture and installation. A plurality of interconnecting lifter mechanisms support the grasper bar above the housing for pivotal movement with it inwardly toward and outwardly from the spindles of the spinning frame. The lifter mechanisms are each of a type realizing precise linear motion, and are simultaneously actuated by a hydraulic cylinder and piston assembly mounted within the cylindrical housing and operatively connected to a rod extending concentrically therewithin. Reciprocatory movement of the rod is transmitted to appropriate links of the lifter mechanisms by interconnecting brackets projecting upwardly through guide slots provided in the cylindrical housing, to impart vertical movement to the grasper bar carried at the upper ends of the lifter mechanisms. Flexible seal means prevent the entry of lint or other foreign matter into the cylindrical housing, yet freely permit guided movement of the projecting brackets longitudinally of the guide slots of the housing. The housing, in addition to preventing lint accumulation upon and possible damage to the components therewithin, shields the bobbin-conveyor and other components of the doffing apparatus from accidental contact by carts and the like moving in the aisle adjacent the spinning frame, and is in turn shielded by a bumper member extending along the full length of the housing on that side thereof facing the aisle.

Limit Micro switches associated with the cylindrical housing and with the rod projecting therethrough sense the relative positions of these members at the completion of each of their various phases of movement, and are suitably connected to the master control circuitry of the apparatus. The presence of an undoffed bobbin upon any one of the spindles is preferably detected by photoelectric means, including a lamp source and receiver respectively mounted at opposite ends of the spinning frame so as to pass therebetween a light beam extending parallel to therow of spindles and above their free upper ends, but below the upper end of a bobbin left mounted on any one of them. Interruption of the beam by an undoffed bobbin upon any one of the spindles preferably stops the doffing operation immediately after the grasper bar has completed its movement upwardly away from the spindles, and prior to its commencement of lateral movement, and may if desired also actuate suitable audible and/or visual alarm means.

The foregoing and other features and advantages of the invention will be apparent from the following description of an illustrative embodiment thereof, which should be read in conjunction with the accompanying drawing, in which:

FIG. 1 is a partially schematic front elevation of a textile spinning frame equipped with automatic doffing apparatus embodying the invention, with various components broken away to indicate indeterminate length or to better reveal details of construction;

FIG. 2 is an enlarged fragmentary front elevation of one of the lifter mechanisms and immediately adjacent components of the doffing apparatus, some of the components being broken away or shown in section;

FIG. 3 is an enlarged fragmentary vertical section taken approximately along line 33 through the bobbin conveyor track and the cylindrical housing at the bottom of the apparauts of FIG. 1, showing one of the interconnecting brackets mounting the housing for pivotal movement;

FIG. 4 is a similar enlarged fragmentary vertical section taken approximately along line 4-4 of FIG. 2, showing one of the assemblies and brackets for imparting pivotal movement to the cylindrical housing;

FIG. 5 is a similar enlarged fragmentary vertical section taken approximately along line 5-5 of FIG. 1, showing the means for detecting the pivotal positions of the cylindrical housing;

FIG. 5A is an enlarged fragmentary perspective view of one of the slotted portions of the cylindrical housing, showing the slot sealing means and also the bumper bar extending along the housing;

FIG. 6 is an enlarged fragmentary perspective view taken approximately along line 6--6 of FIG. 1, showing in full lines the bobbin grasper bar in its inoperative position, and indicating by arrows and by phantom lines the path of movement thereof; and

FIG. 7 is a schematic representation of part of the hydraulic circuit of the apparatus, also schematically showing by broken lines a related part of the apparatus electrical circuitry.

Referring more particularly to the drawings, the spinning frame or like machine 10 schematically and fragmentarily shown in FIG. 1 is of a conventional construction including opposite head and foot ends 12, 14 between which there extend, on each side of the machine and intermediate its height, a stationary spindle rail 16 mounting a row of upright bobbin-receiving spindles 18 which during operation of the machine 10 are rotated about their axes and traversed by a vertically movable ring rail 20 as yarn is directed thereto from the machines drafting elements and creel (not shown) disposed thereabove. Machine 10 is permanently equipped with automatic bobbin-doffing apparatus generally of the type disclosed in U. S. Pat. No. 3,370,41 l and including, on each side of the machine, a bobbin grasper bar 22 and an endless bobbin conveyor 24 extending horizontally beneath the full length of the row of spindles 18. Spaced along the length of conveyor 24 are a plurality of bobbin-supporting pegs 26, on alternate ones of which empty bobbins B are mounted in upright fashion by a loading mechanism (not shown) at foot end 14 of machine 10 as the upper flight of conveyor 24 is moved, during each loading operation, toward head end 12. Upon completion of each bobbin-loading operation, which may transpire at any convenient time between doffs of machine 10, conveyor 24 is halted with the alternate empty pegs 26 thereon positioned beneath and in precise vertical alignment with corresponding ones of the spindles 18 and also corresponding ones of a plurality of bobbin grasper elements 28 spaced longitudinally of and depending downwardly from the grasper bar 22 then disposed in its inoperative position beneath the lower ends of spindles l8 and above the upper ends of the empty bobbins B upon conveyor 24. While grasper elements 28 may be of other constructions, they preferably are of the inflatable type adapted to be inserted into the open upper ends of bobbins and then expanded, as by pressurized air directed to their interiors from a suitable source (not shown) communicating with the hollow interior of bar 22, into firm grasping engagement with the bobbins interior surfaces.

When machine 10 has completed a spinning cycle, a doffing operation is commenced either manually or automatically by appropriate signals from master control (FIG. 7) of the doffing apparatus. Upon completion of certain preliminary steps in the doffing operation, grasper bar 22 is moved from its inoperative position (see FIG. 6, wherein double-headed arrows indicate the paths of grasper bar movement) in a forward or outward direction a distance sufficient to clear the overlying spindle rail 16, then upwardly to an elevation above the full bobbins B upon spindles 18, then inwardly a distance sufficient to again bring its depending grasper elements 28 into precise vertical alignment with spindles l8 and the full bobbins B mounted thereon, and finally downwardly a distance sufficient to insert grasper elements 28 within the open upper ends of bobbins B. Bobbins B are then grasped by inflation of elements 28, doffed from spindles 18 and placed upon the empty alternate pegs 26 of conveyor 24. This is achieved by grasper bar 22 returning along the aforesaid path of movement to its original inoperative position, and then moving downwardly a distance sufficient to seat the lower ends of the bobbins upon the empty conveyor pegs 26 in alignment therewith. Elements 28 are now deflated, and bar 22 moves upwardly from the released full bobbins B to its original inoperative position, after which conveyor 24 moves longitudinally the slight distance necessary to vertically align the empty bobbins B thereon with grasper elements 28. Bobbins B are then grasped, transported upwardly and vdonned upon spindles 18 by bar 22, which thereafter returns to its original inoperative position beneath spindles 18, in a sequence of movement steps such as described previously. At any convenient time during normal spinning operations of machine 10, which are then resumed, the upper flight of conveyor 24 is moved back toward foot end 14 of machine as the full bobbins B are removed therefrom' by an unloading mechanism (not shown) there located.

GRASPER BAR SUPPORTING AND POSITIONING MECHANISM Referring now primarily toFIGS. 2-6, conveyor 24 is in accordance with the present invention supported by a track 30 of unique construction and placement. Track 30 has a hollow and generally rectangular cross- 88. As is schematically indicated by broken lines in FIG. 7, valve 84 is operatively connected to the master electrical control 90 of the doffing apparatus and, upon receiving an appropriate electrical signal therefrom, directs fluid from line 80 through check valve 86 to the lower ends of each assembly 46, causing simultaneous retraction of their pistons and rods and thus causing brackets 44 to pivot housing 38 in a clockwise direction, as viewed in FIGS. 4 and 6, through an arc of approximately 12. Valve 88 so throttles the exhaust flow of hydraulic fluid passed from the upper ends of assemblies 46, through valve 84 and to return line 82, as to sectional shape, and preferably is formed, from a suitable metal such as aluminum, in a single unitary length by extrusion techniques, joined rigidly to adjacent samsons 35. When soformed, problems of joint alignment surface of the upper wall of track 30 seats and guides the upper flight of conveyor 24, while the lower conveyor flight is supported within track 30, where it is shielded from lint and the like, by inwardly projecting flanges 30 there .provided. Track 30 extends substantially the full length of machine 10 parallel to and directly beneath spindle rail 16, and is rigidly secured to the machine's frame at longitudinally spaced intervals by another bracket (not shown) to its samsons 35.

The forward or outer vertical face of track 30 provides an accurate mounting surface for a plurality of bearing blocks 36 bolted or otherwise rigidly secured to it at longitudinally spaced intervals. A cylindrical housing 38 extendshorizontally substantially the full length of the row of spindles 18 through the aligned bores of bearing blocks 36 and is supported thereby for controlled pivotal movement about its central axis. Studs 40 connected to blocks 36 mount a bumper bar 42 in spaced parallel relationship to housing 38, on that outer side thereof adjacent the servicing aisle customarily provided next to machine 10, which bumper 42 extends the full length of housing 38 and shields the same from being accidentally engaged by carts and like traffic customarily moving along such an aisle.

Pivotal movement is imparted to housing 38 by a plurality of hydraulic piston and cylinder assemblies 46 connected to conveyor track 30 by brackets 33 and bolts 32, and also to housing 38 at spaced intervals along its length by means of suitable brackets 44 rigidly secured thereto. As is best shown in FIG. 4, each bracket 44 includes a bell-crank arm 44 extending downwardly and inwardly from housing 38 to a pivotal connection with the piston rod component of the associated assembly 46. All of the assemblies 46 are connected for simultaneous operation in parallel branches of a hydraulic circuit (see FIG. 7) including fluid supply and return lines 80, 82, solenoid-actuated valve 84, check valves 86, 86' and adjustable throttle valves 89,

insure smoothness and uniformity of the aforesaid movement. Upon receipt of another appropriate signal from master control 90, valve 84 directs fluid from line through check valve 86 to the upper ends of assemblies 46, similarly causing return pivotal movement of housing 38 in a counter-clockwise direction to its original position, the exhaust fluid passing at this time from the lower ends of assemblies 46 being throttled by valve 88. Secured in any suitable manner to conveyor track 30 (see FIG. 5), as by brackets 34, are a pair of vertically spaced limit switches 64, 66 connected to master control and disposed in the path of movement of an inwardly extending arm 68 secured to and pivotally movable with housing 38. When housing 38 reaches the end of its outward pivotal movement, tripping of switch 64 by arm 68 notifies master control 90 of such occurrence. A signal is similarly directed to master control 90 upon return pivotal movement of housing 38 to its inward position, by arm 68 then engaging and actuating switch 66.

While for purposes of illustration only four assemblies 46 are shown in FIG. 7, more of the assemblies and of the associated brackets 44 would be provided if 'required, by the length of machine 10 and housing 38,

to prevent objectional torsional deflection of housing 38 during its aforesaid pivotal movement.

A larger hydraulic piston and cylinder assembly 50 mounted concentrically and rigidly within housing 38 (see FIG. 2) has its piston component connected to a rod 52 which extends from both ends thereof axially of housing 38 through longitudinally spaced supporting bearings 53 and spool-like guide brackets 54 respectively secured to housing 38 and threaded portions of rod 52, and also through coil springs 55 disposed for reasons subsequently discussed between each bracket 54 and bearing 53. At head end 12 of machine 10, rod 52 terminates inwardly of the closed end of housing 38,

but at the opposite end of the housing projects through a suitable seal (not shown) and along foot end 14 of machine 10 in adjacent relationship to a plurality of frame-mounted limit switches 70. Switches 70 are engaged and tripped upon reciprocation of rod 52 by an actuating element 72 secured to the projecting rod portion. As is shown in FIG. 7, switches 70 are electrically connected to master control 90, as is the solenoidoperated valve 92 producing reciprocatory movement,

of rod 52 by selectively directing hydraulic fluid to and from opposite ends of assembly 50 via hydraulic pressure and return lines 80, 82 and adjustable throttle valve 94.

Each bracket 54 includes an outer portion having an upstanding fin 54 projecting therefrom, and an inner portion 54" which is concentric and adjacent an interiorally threaded sleeve 57 to facilitate precise initial positional adjustment of the bracket longitudinally of the threaded portion of rod 52 encircled thereby. Each fin 54' projects upwardly from housing 38 through one of a plurality of elongate guide slots 56 provided through it. Slots 56 are provided with resilient seal means which prevent the passage of lint and other foreign matter into housing 38, yet do not impede guided movement of fins 54', during axial reciprocation of rod 52, by and longitudinally of the slots. Each such seal comprises two strips of rubber or similar resilient material 58, 58' (see FIGS. 4 and 5A) extending the full length and secured in any suitable manner upon opposite sides of the slot 56 sealed thereby, the strips being of such a width that their adjacent longitudinal edges overlap or at least abut intermediate the width of the slot. The resiliency of strips 58, 58 is such that immediately adjacent bracket fin 54' they deflect upward to permit its passage, but elsewhere along the slots length retain their overlapped and shielding positions.

A plurality of identical lifter mechanisms 59, two of which are shown in FIG. 1, of the Scott-Russell straight-line type extend upwardly from housing 38 at equally spaced intervals throughout its length. As is better shown in FIG. 2, each lifter mechanism 59 includes a first link 60 connected at its lower end to a corresponding one of bracket fins 54 for unitary movement with bracket 54 longitudinally of and pivotally about the axis of housing 38, and for pivotal movement relative to bracket 54 and housing 38 in a generally vertical plane. The upper end of link 60, which as shown in FIG. 6 is inwardly offset somewhat from its lower end, supports and is pivotally connected to grasper bar 22 by a bracket 61. The second link 62 of each lifter mechanism 59 is similarly connected, for relative pivotal movement in a generally vertical plane, at its upper end to an intermediate portion of link 60 and at its lower end to one of the brackets 44 through which pivotal movement is imparted to housing 38 by piston and cylinder assemblies 46. Reciprocatory movement of rod 52 produces unitary guided movement of brackets 54 and the lower ends of links 60 toward or away from brackets 44 and the lower ends of links 62, which by the interaction between the links produces linear upward or downward movement of the upper ends of links 60 and the grasper bar 22 supported thereby.

The desired movement of grasper bar 22 during the doffing operation and along the previously-described path indicated by the arrows in FIG. 6 is produced through the aforesaid linkages and mechanisms by selective actuation of valves 84, 92 and hydraulic assemblies 46, 50 by master control 90. Actuation of assemblies 46 produces inward and outward grasper bar movement through brackets 44, housing 38 and the edges of guide slots 56, brackets 54, links 60, 62 and brackets 61. Actuation of assembly 50 produces upward and downward grasper bar movement through rod 52, brackets 54, 44, links 60, 62 and brackets 61. Verification of the completion of each phase of the grasper bars movement is obtained, and transmitted to master control 90 before the latter permits commencement of the next succeeding movement phase, by actuation of an appropriate one of the limit switches 70 by actuator 72, in the case of upward and downward movement of bar 22, and by actuation of switch 64 or 66 by actuator arm 68, in the case of inward and outward bar movement. Such verification greatly lessens the possibility of the doffing apparatus and/or machine 10 being severely damaged if a malfunction should inadvertently occur.

Removal of full bobbins B from spindles 18 constitutes one of the more difficult steps in each doffing operation. As grasper bar 22 is moved upwardly from spindles 18, following insertion and inflation of its grasper elements 28 within the open upper ends of the bobbins B mounted upon such spindles, all bobbins B should be raised with bar 22 to an elevated position wherein their lower ends are above the tips of the spindles. It is possible, however, that due to a faulty bobbin, spindle clutch or other uncontrollable variable, one or more bobbins B might be inadvertently left fully or partially seated upon its respective spindle 18. If that condition existed and the doffing operation proceeded without its correction, considerable damage would be done either to the doffing apparatus and/or to machine 10, either during the next-succeeding outward movement of grasper bar 22 or at that subsequent time in the doffing operation when an attempt would be made to seat an empty bobbin B upon the then still undoffed spindle 18. To prevent such an occurrence, the present invention provides reliable but inexpensive stopmotion means for detecting the presence of any undoffed bobbin still remaining upon any of the spindles 18 at the aforesaid point in the doffing operation. This is preferably of the photoelectric type, including a light source 74 and light receiver 76 (FIGS. 1 and 6), respectively mounted at opposite ends of the machine 10, as upon the cabinets of head end 12 and foot end 14, for passage therebetween of a light beam parallel to and closely adjacent the row of spindles 18. Preferably the beam is directed immediately above the upper ends of spindles 18, where it would underlie the lower ends of the doffed bobbins B suspended from grasper bar 22 .but would be blocked by any bobbin B left undoffed upon any one of the spindles, but the beam might be directed adjacent any portions of the spindles where a similar result could be obtained. Receiver 76, which may be of either the light or dark-actuated type, forms part of a suitable stop-motion circuit which preferably, as indicated in FIG. 7, is connected to master control in a manner causing the doffing operation to be immediately stopped if an undoffed bobbin B should be detected. Alternatively or additionally, the stop-motion circuit may actuate suitable visual and/or audible alarm means (not shown).

It will be noted that when grasper bar 22 is disposed in its inoperative position, not only it but also all components of the lifter and associated mechanisms are at an elevation below that of spindle rail 16 and the spindles 18 carried thereby. This affords free access to the spindle, drafting and creel areas of machine 10 for servicing purposes during normal spinning operations. End-down piecing, cleaning and/or other servicing functions can if desired be performed by mobile units suspended from or above spindle rail 16 of machine 10, in accordance with practices now followed in some mills, without the doffing apparatus in any way constituting an obstruction. The inward offset provided at the upper end portions of links 60 of each of the various lifter mechanisms 59 (FIG. 6) affords additional clearance for any such servicing unit which might extend downwardly somewhat from spindle rail 16 of machine 10.

It will also be noted that while grasper bar 22 is in its inoperative position, as well as at other times, conveyor 24 is shielded from accidental impacts from carts and the like by housing 38, which also shields the hydraulic assembly 50 and rod 52 therewithin and is in turn shielded from such impacts by bumper bar 42. The accumulation of lint and other debris upon the lower flight of conveyor 24, assembly 50, rod 52, bearings 53 and brackets 54 is discouraged by the enclosure of these components within track 30 or housing 38.

The coil springs 55 disposed within housing 38 between adjacent bearings 53 and brackets 54 exert a biasing force upon the brackets insuring that bar 22 will not inadvertently drop downwardly from its inoperative position even if the hydraulic flow to assembly 50 should fail or be shut off for some reason. Springs 55 also assist initial upward movement of bar 22 by assembly 50 through mechanisms 59, at which time the positions of links 60, 62 affords the least mechanical advantage.

While a specific embodiment of the invention has been shown and described, it will be appreciated that this was for purposes of illustration only, and not for purposes of limitation, the scope of the invention being in accordance with the following claims.

That which is claimed is:

l. In an automatic bobbin doffing and tube donning apparatus for servicing a textile machine having a plurality of upright bobbin tube receiving spindles mounted in'a row extending longitudinal said machine, said apparatus including a grasper bar extending parallel to and the entire length of said row and having thereon a plurality of bobbin tube grasping elements for at desired times grasping bobbins to be doffed from or empty bobbin tubes to be donned upon said spindles, the improvement comprising support means, respectively,

for moving said grasper bar laterally into and out of vertical alignment with said row wherein said grasping elements are positioned into and out of alignment with said spindles and for moving said grasper bar vertically between a lowered position wherein said grasper bar and said support means are entirely beneath said row and an elevated position wherein said grasper bar is above said row,

said support means being pivotally interconnected at a lower end thereof to said machine for said lateral moving and at an upper end thereof to said grasper bar for said vertical moving.

2. The improvement as in claim 1, wherein said support means comprises a rod extending longitudinally the lower end of said machine and interconnected therewith for axially reciprocatory movement relative thereto,

a plurality of hinge-linked lifter mechanisms attached to said rod at an end, interconnected with said machine at an end and hingedly-linked to said grasper bar at another end for unitary pivotal movement of said lifter mechanisms and said grasper bar and for reciprocatory movement of said lifter mechanisms with said rod,

pivotal movement means for imparting said pivotal movement to said lifter mechanisms and said grasper bar in unison about the axis of said rod, and

reciprocatory axial movement means for imparting said reciprocatory movement to said rod and said lifter mechanisms to move said grasper bar vertically between said lowered and elevated positions.

3. The improvement as in claim 2, wherein said reciprocatory axial movement means includes a hydraulic piston and cylinder assembly attached to said rod to impart reciprocatory movement thereto.

4. The improvement as in claim 2, wherein said pivotal movement means includes a hydraulic cylinder and piston assembly carried by said machine and interconnected with said lifter mechanisms for imparting said pivotal movement to said lifter mechanisms and said grasper bar in unison about the axis of said rod.

5. The improvement as in claim 2, further including switch means for detecting the pivotal and vertical positions of said grasper bar.

6. The improvement as in claim 5, wherein said switch means includes a switch actuating member interconnected with and pivotally movable with said lifter mechanisms and a coacting member mounted in the path of pivotal movement of said switch actuating member to coact therewith for sensing pivotal positions of said lifter mechanisms and said grasper bar.

7. The improvement as in claim 5, wherein said switch means includes sensing means operatively associated with said rod for sensing reciprocatory positions thereof and thereby vertical positions of said grasper bar.

8. The improvement as in claim 2, wherein said support means further comprises an elongate housing interconnected with said machine, extending adjacent the lower end thereof, and generally parallel to and substantially the entire length of said row,

wherein said pivotal movement means mounts said housing,

wherein said rod extends longitudinal of and is mounted within said housing and is reciprocatable relative thereto, and

wherein said hinge-linked lifter mechanisms interconnected at an end thereof to said machine are interconnected therewith through said housing such that said housing is pivotable with said lifter mechanisms.

9. The improvement as in claim 8, wherein said hinge-linked lifter mechanisms attached at an end thereof to said rod are so attached through bracket means, wherein said housing is formed with a slot means extending longitudinal thereof, wherein said bracket means projects through said slot means, wherein said housing has flexible seal means displaceable by said bracket means projecting through said slot means, and wherein said seal means overlays said slot means to shield it and the interior of said housing.

10. The improvement as in claim 9, wherein said seal means includes a plurality of strips of resilient material secured to and extending longitudinal said housing on opposite sides of said slot means, said opposing strips thereof having longitudinal edges in at least abutting relation to one another intermediate the width of said slot means. 

1. In an automatic bobbin doffing and tube donning apparatus for servicing a textile machine having a plurality of upright bobbin tube receiving spindles mounted in a row extending longitudinal said machine, said apparatus including a grasper bar extending parallel to and the entire length of said row and having thereon a plurality of bobbin tube grasping elements for at desired times grasping bobbins to be doffed from or empty bobbin tubes to be donned upon said spindles, the improvement comprising support means, respectively, for moving said grasper bar laterally into and out of vertical alignment with said row wherein said grasping elements are positioned into and out of alignment with said spindles and for moving said grasper bar vertically between a lowered position wherein said grasper bar and said support means are entirely beneath said row and an elevated position wherein said grasper bar is above said row, said support means being pivotally interconnected at a lower end thereof to said machine for said lateral moving and at an upper end thereof to said grasper bar for said vertical moving.
 2. The improvement as in claim 1, wherein said support means comprises a rod extending longitudinally the lower end of said machine and interconnected therewith for axially reciprocatory movement relative thereto, a plurality of hinge-linked lifter mechanisms attached to said rod at an end, interConnected with said machine at an end and hingedly-linked to said grasper bar at another end for unitary pivotal movement of said lifter mechanisms and said grasper bar and for reciprocatory movement of said lifter mechanisms with said rod, pivotal movement means for imparting said pivotal movement to said lifter mechanisms and said grasper bar in unison about the axis of said rod, and reciprocatory axial movement means for imparting said reciprocatory movement to said rod and said lifter mechanisms to move said grasper bar vertically between said lowered and elevated positions.
 3. The improvement as in claim 2, wherein said reciprocatory axial movement means includes a hydraulic piston and cylinder assembly attached to said rod to impart reciprocatory movement thereto.
 4. The improvement as in claim 2, wherein said pivotal movement means includes a hydraulic cylinder and piston assembly carried by said machine and interconnected with said lifter mechanisms for imparting said pivotal movement to said lifter mechanisms and said grasper bar in unison about the axis of said rod.
 5. The improvement as in claim 2, further including switch means for detecting the pivotal and vertical positions of said grasper bar.
 6. The improvement as in claim 5, wherein said switch means includes a switch actuating member interconnected with and pivotally movable with said lifter mechanisms and a coacting member mounted in the path of pivotal movement of said switch actuating member to coact therewith for sensing pivotal positions of said lifter mechanisms and said grasper bar.
 7. The improvement as in claim 5, wherein said switch means includes sensing means operatively associated with said rod for sensing reciprocatory positions thereof and thereby vertical positions of said grasper bar.
 8. The improvement as in claim 2, wherein said support means further comprises an elongate housing interconnected with said machine, extending adjacent the lower end thereof, and generally parallel to and substantially the entire length of said row, wherein said pivotal movement means mounts said housing, wherein said rod extends longitudinal of and is mounted within said housing and is reciprocatable relative thereto, and wherein said hinge-linked lifter mechanisms interconnected at an end thereof to said machine are interconnected therewith through said housing such that said housing is pivotable with said lifter mechanisms.
 9. The improvement as in claim 8, wherein said hinge-linked lifter mechanisms attached at an end thereof to said rod are so attached through bracket means, wherein said housing is formed with a slot means extending longitudinal thereof, wherein said bracket means projects through said slot means, wherein said housing has flexible seal means displaceable by said bracket means projecting through said slot means, and wherein said seal means overlays said slot means to shield it and the interior of said housing.
 10. The improvement as in claim 9, wherein said seal means includes a plurality of strips of resilient material secured to and extending longitudinal said housing on opposite sides of said slot means, said opposing strips thereof having longitudinal edges in at least abutting relation to one another intermediate the width of said slot means. 